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Karate shortens your lifespan

Wasn't sure if this should go in self protection instead... Apparently karate training may not be as healthy as we suspect. High ranking karate masters historically tended not to live as long as we might have thought, and different styles have different effects so it appears to be training habit related.

My experience is of almost constant low level injury, particularly as the training sessions intensity increase.

I’m not buying this at all. The first thing is that you’d need to take out any lifestyle issues before any worthwhile conclusions can be drawn.

Mabuni – used as an opening example in the video – was a very heavy smoker (1889 – 1952: Died age 63)

Motobu said “It is important for the karateka to drink heavily and engage in other fun activities otherwise their karate will lack character” (1870 – 1944: Died age 74)

Kyan said, “To be a true martial artist, training in karate is not enough. One must associate with prostitutes and get involved in drinking competitions” (1870 – 1945: Died age 75)

I’d suggest that it was wider lifestyle, and not karate, which was the major contribution to any reduction in lifespan.

There are lots of other problems too.

Gichin Funakoshi is used in the video (8:15) as an “exception” and it’s noted that he may be an expectation because of his lifestyle (eating little meat, low alcohol consumption, etc.). This would again suggest that lifestyle is the most likely contributory factor and that his karate did not override wider lifestyle choices. Surely that works both ways!

There’s loads of other examples that leapt to mind when viewing the video i.e. Kimura – who died of a heart attack at 54 – was also known to be a heavy drinker ... a known and scientifically verified contribution to heart attacks! From the NHS website: “Excessive alcohol consumption can cause high blood pressure and increased blood cholesterol levels, thereby increasing the risk of developing CHD.” http://www.nhs.uk/Conditions/Heart-attack/Pages/Causes.aspx Surely this known factor needs ruled out before bold claims can be made about karate!

Do we know which of the 118 karateka looked at smoked, had a poor diet, had diabetes, had high blood pressure, drank more than they should, came from a family with a history of heart disease, and so on? When I looked at the names listed, quite a few of those listed were known to have one or more of the above, so it’s most logical to assume that the known contributory factors are at work; not ignore them and put it all down to karate! For those we don’t know the background of, why make the logical leap of assuming karate is the cause? Seeing as the known causes have not been ruled out, it is illogical to discount them. With such a small sample size, these variables are going to make a significant contribution to individual lifespans and they can’t be overlooked. You hear hoof beats you should think horses, not zebras or unicorns :-)

The sample size is also way too small to state anything meaningful. They looked at 118 practitioners, which would be nowhere near enough to draw meaningful conclusions, especially when you need to rule out all the variables in lifestyle.

The deeming of a death as premature, being based on average life expectancy at birth statistics (a data pool of millions) when compared against specific examples (just 118 people) means that the difference is utterly meaningless. It’s way too small a sample to support to the very bold claims that have been made.

The blurb for this books states, “Doctors practice a system called “Evidence based practice” abbreviated to EBP, this is a process of analyzing data to decide on a scenario and ultimately prevention or treatment. We as martial artists should also train with an evidence based practice approach given recent decades has resulted in the collection of extensive data for street fighting statistics, sports and health.”

So when looking at medical “evidence based practise” we can also look at “Effects of martial arts on health status: A systematic review” published in the Journal of Evidence Based Medicine (Nov 2010); which included randomized controlled trials and controlled clinical trials on the health effects of martial arts. This paper concluded that further research was needed but “most studies on the health effects of martial arts found positive results.” This is a scientific paper that has been submitted to peer review. It’s more much more than the check of the age of death of 118 karateka and therefore presents much more reliable data and conclusions.

The blurb for the book also states, “In generating the data for the book, we factored in the decade and year sensei(s) died in, their geography and given those variables, at what age they should have died at using what are called life expectancy at birth statistics and life expectancy by age statistics. Although the books focuses on sensei’s ages of death in recent decades, we also compare to famous karate sensei who were born in the 1800s. Furthermore, we compare the data to other Western sports, Olympians and martial arts like judo. All of these groups allow us to flush out hypotheses around the variables that may be affecting lifespan and talk about diagnostics or possible training or behaviour change.”

Again, what about smoking and drinking? Diet? Family history? These things and known to have a HUGE influence on life expectancy and it strikes me as being very wrong to ignore these things and put everything down to karate!

Actually, to be fair, they bring these known factors in when the figures don’t match their hypothes (i.e. with Funakoshi) but seem to ignore the influence despite it being a much more likely cause than the practise of karate.

It strikes me as being tantamount to going to a football game, picking a very small sample of people, and testing blood pressure. I then ignore their health, diet, weight, etc (all things proven to contribute to high blood pressure) and make the claim that all those with high blood pressure have that medical problem because they are football supporters … and those with low blood pressure I explain away by saying they would have high blood pressure, because they are football supporters, if weren’t for their good health, diet, weight, etc … in short, all the things we know contribute to high blood pressure! It’s logically untenable to make the claims presented.

To be fair to the writers of this book, I’d have to read it fully before coming to firm conclusions. However, it does not look like the book was a study (in the scientific sense) and it has not been subject to peer review. I therefore immediately have questions around methodology and the lack of peer review. In short, the video hardly makes a compelling case for their claim and I'm not left feeling like I need to rush to find out more.

I could also look at the age of death of a similar number of karateka very quickly (http://en.wikipedia.org/wiki/List_of_karateka) but without knowing about all the other factors (their diet, smoking drinking, family history, etc.) it’s a meaningless set of figures.

A quick look at the lifespans of some of the great and good from my own lineage revels nothing to worry about (random names who leap to mind).

Sokon Matsumura Lifespan: 93 years

Anko Azato Lifespan: 80 years

Anko Itosu Lifespan: 85 years

Gichin Funakoshi Lifespan: 88 years

Hironori Otsuka Lifespan: 90 years

I’m not seeing Funakoshi as being some lone exception here?

Indeed, this is what Funakoshi himself said (Karate-Do: Kyohan):

“My esteemed teachers, the late masters Itosu and Azato, were both very weak in their childhood, but after starting to train in karate as means of improving their health, they developed so much that the seemed like different people compared to their old selves and lived to become famous, in our times, as old masters. Master Itosu lived to the venerable age of eighty five, and Itosu to that of eighty. Master Azato’s own teacher, Master Matsumura lived to be over ninety years of age. Other contemporary karate experts such as Yamaguchi, Aragake, Chibana, Nakazato, Yahiku, Tokashiki, Sakihara, and Chinen, have all lived to be over eighty. These examples are indicative of the role of karate as a superior method of maintaining one’s health.”

Again, this is all anecdotal and does nothing to establish that karate makes you live longer of course. But the claim that pointing to Funakoshi is like saying “I know this guy who has been smoking all his life and is now eighty five” is not a good analogy!

Funakoshi was far from being a sole example of a karateka living to a good age; lots of them did … which may or may not have anything to do with karate! It does, however, make it very hard to liken karate to smoking when it comes to negative health effects when so many of them are living as long, or longer, than Funakoshi did.

The video also makes the claim that Funakoshi “banned sparring” and the lack of injures may have also contributed to his longevity. That is plain wrong! Funakoshi’s master text states:

“in free sparring there is no set rules as to who will be the attacker or the defender, and so either one may freely attack … [free sparring] maybe compared to an actual duel as in other martial arts where all possible defensive and offensive techniques can be fully used. It is important to keep this in mind and really understand the exquisite mystery inherent in free sparring.”

I’d ask what is the source for the claim “Funakoshi banned sparring”? In his master text he emphasises its importance and speaks of it positively. I’m not aware of anything in his writings that states he banded sparring, and I’m aware of loads that emphasises its importance.

The claim is also made that Itosu “openly stated that health may not go hand in hand with budo”. The only statement that I’m aware of is the concern that practising with large amounts of tension (as some do with Sanchin kata) causes problems with blood pressure and that this can lead to an early death (this is from memory so I could be wrong, but I recall the statement being along the lines of Itosu saying that people who did such practise tended not to live long beyond eighty?). This is a long way from saying that karate as a whole can be bad for one’s health, especially when we also have Itosu saying, “The primary role of karate practise is to benefit one’s health” (Ten Precepts, 1908). If this is the quote they are referring to, then it’s a specific form of practise that Itosu is expressing concern about, and not karate, or budo, as a whole.

As I say, I’d have to see the book to give a totally fair assessment, but based on the video they’ve put together to promote the book I have very strong reservations. There are demonstrable problems with:

Method i.e. no sign of taking into account lifestyle, etc and the known effects that has.

Statistics i.e. the very small sample being compared against much larger national statics can’t give anything meaningful because any fluctuation is most likely due to the huge differences in scale i.e. it’s statically insignificant. To give an example, if I toss a coin one million times, I’ll get heads roughly 50% of the time. I’m going to stop typing and toss a coin ten times now … I got heads seven times (70% of the time is was heads) … I’ve just took a sip of coffee … and now I’ll toss the coin another 10 times … this time I got heads 4 times (40% of the time it was heads). Using such a small sample I could make the claim that drinking coffee causes a 30% reduction in the number of coin flips that land heads! If I did a lot more coin tosses, the variations that appear in these small samples would be “ironed out” and it would become clear coffee drinking has zero influence on coin tosses. Similarly, taking a small sample and therefore potentially drawing false conclusions is what is being done here when you compare a very small number (118 karateka) against national life expectancy statistic’s (millions of people). It is meaningless statistically insingificant data you can draw no solid conclusions from because fluctuations from the mean adverage (gernated from a huge numner of people) would be expected in such a comparatively small sample size.

Errors and Quote Mining i.e. the video makes some claims which are false (i.e. Funakoshi banned sparring) and would seem to take some quotes out of context i.e. the Itosu health quote (?) and the ignoring of alternate quotes which give a view not in keeping with the conclusion.

Confirmation Bias (seeking data that supports your claim, while ignoring data which does not) i.e. pointing to Funakoshi as an exeption (which he really wasn’t anyway, even according to Funakoshi himself) but explaining it away as his good lifestyle choices, but ignoring the role bad lifestyle chocies may have played on those who died younger (as is well documented in some of the examples given).

So in conclusion, there are masses of studies that show exercise is good for your health. There are even studies (published and peer reviewed evidance based medical studies) that show martial arts specifically are good for your health. There are no scientific studies that show karate, specifically, is bad for you. Based on what is presented in the video, there are demonstrable problems and hence the conclusion reached is far from secure.

In short, we are all going to die of something, and I’m very confident that karate will not be that something and will contribute to my longevity. I’m happy to change my views in the receipt of strong evidence. This is not strong evidence.

I would also add that not only was Funakoshi in favour of some form of pressure testing of karate skills, he even mused about the possibilities of using body armour so that it could be used as a testing measure in gradings.

Funakoshi wrote that "With continuing research it is not unfeasible that as with Judo and Kendo our Karate, too, might incorporate a grading system through the adoption of protective gear and the bannong of strikes to vital points. In fact, I think it is important to move in that direction."

From most data I can find the average life expectancy for Japan at the turn of the century was around 40 years. This would actually make Mabuni (63), Kyan (75) and Motobu (74) considerably longer lived than the average for their peer group, despite the poor lifestyle choices! There were rapid increases during the 20th century (mostly to do with the rapid modernizing of medical technology and general societal affluence) but even by the 1950s the average life expectancy was still only around 60. It only went up to the high level that is so well known today after the 60s.

Are they actually trying to compare the turn of the century master's lifespans to the average for Japan today? That is very unsound methodology indeed!

Lets also not forget that many of the masters listed that died are in the time span of WW2 and the devastation that happened to the Okinawans and their lifestyle.

To do a more complete "study", you would need to look at life span of non-karate okinawans and look at known lifestyle factors to see if there was a significant difference in life span between all factors outside of karate.

For example, what was the lifespan of a heavy drinking smoking okinawan that didn't practice karate?

I would advise those posting here to read something before you try and critique it. It seems to me that people here are forming a summary of something they have not reviewed/researched/read.... Many of the questions/criticism in this thread are addressed in the depths of the book.

I work in the healthcare industry and in answer to those that question lifespan statistcs, the study discussed in this thread used the same industry and research standards that are used by life insurane agencies, national health bodies, medical university studies etc. So I don't really understad why they are being questioned as an approach backed up by the appropriate statistics. In fact, 118 people is not a small number compared to many patient group studies when being compared to the larger population lifespan data via what is called life expectacy at birth prediction tables and life at death prediction tables etc. (none of the above tbread comments are accurate regarding life expectancy data and methods of analysis - tbe book opens with an introduction to this topic - although the above comment/graph lists an important part of the approach and historical data).

Karate of course is not the only sport that appears to reduce lifespan and the book talks about some others - other studies like this one also tease out the variables around diet, region, occupation, training types, psychology and the list goes on. As the book states in one part, peolpe have to be aware of the difference in exercise in regards to whether we are training for health, fitness or enjoyment as they are all different things (and the government health bodies recognize this).

For example, comments re Funakoshi is a good question and it is dissected in the study/book in multiple places (covering the different variables) very thoroughly as why he, and a number of others, likely bucked the trend.

Karate is not the only anaerobic physical activity when done at high levels that appears to reduce/not help lifespan. Fitness, conditioning and health are all different things. The question is whether one wants to guess, or do some reading and research to become informed to understand what such links may be - be it physical or may also extend to karate culture/lifestyle in certain styles in some dojos/people....

Many of the questions/criticism in this thread are addressed in the depths of the book … In fact, 118 people is not a small number compared to many patient group studies when being compared to the larger population lifespan data via what is called life expectancy at birth prediction tables and life at death prediction tables etc

Can I ask how the book goes about accounting for known determining factors on lifespan such as diet, drinking, smoking, etc? What controls are used is this regard? Were the medical records of all the karateka known?

Can I also ask how 118 people was arrived at as being a sample size? As a layman, I would expect patient group studies to be done on patients; whose medical history is well known. It is therefore possible to work with much smaller numbers (i.e. all participles were males in their 50’s with angina, etc). With such a group you could more easily determine statically significance and hence the validity of the null hypothesis. With a group who are worldwide, and who’s only known common factor is the practice of karate, then 118 would strike me a being way too low.

To determine if there was any statistical significance was (once all known variables were accounted for i.e. diet, drink, age of death of family members, etc) a typical p-value of 5% reached? I would have thought that very hard to do with just 118 people, which is why a much higher sample size would be needed.

I take your point about how reading the book would put us in a better position to critique. I do, however, stand by what I said in the above post:

“To be fair to the writers of this book, I’d have to read it fully before coming to firm conclusions. However, it does not look like the book was a study (in the scientific sense) and it has not been subject to peer review. I therefore immediately have questions around methodology and the lack of peer review. In short, the video hardly makes a compelling case for their claim and I'm not left feeling like I need to rush to find out more.”

The burden of proof lies with those making the claim. I would be happy to buy the book and read more, if it were not for the fact that what has been put forth, so far, does not convince me it is necessary.

If they were to explain the 118 sample size (why that number?), make public whether the p-value of 5% was reached with that small sample size, demonstrate how known factors such diet, drink, smoking, etc could be safely put to one side, show how the protocols for such studies had been adhered to, and point to where the findings had been published for peer review, then I, along with many others, would be very keen to know more.

If they want to sell more copies of the book, then that would be the way to go. I would however point out that true scientific papers don’t require people to pay for them in order to critique them. I get that a book takes time and effort and it’s only right that people be expected to pay for that. However, if the findings are that strong, then publish the findings as a legitimate paper. The validity of that paper is what will get people to want to but the book. The absence of such a paper has the opposite effect and leaves me content with the decision that such a purchase is not needed.

A very bold medical claim has been made, but the evidence for that claim has not gone through the normal protocols and procedures needed to legitimately make such a claim. That alone will be enough for most people reject what has been claimed. They don’t need to buy the book in order to observe these facts.

I had a quick look at the primary section of the book where p values for statistical significnce are reported and counted 26 "p values" related to stats of significance (primarily using Gabriel post-hoc tests, t-tests, Dunnett significance tests and Welch tests - not to claim i understand each of these as i am not a university researcher with a PhD as was the guy who contributed this part to the book ). So to answer your question there were alot. Of course the book quotes other research studies where differing sports also show reduced rather than enhanced lif expectancies and the "p values" are of course spread acoross many of the different variables discussed above and some show significance and others suggest not being significant. In terms of the complexity of the results and variables, trying to sum up what is around 250 pages of data and disucssion, simply isn't something I will attempt to do across the styles, eras, cultures, drinking habits and personality traits all factored in to the disucssions in the book...

Sounds nonsensical to me, to be blunt. Why/how would Karate be different from similar forms of exercise, and why would.it lower lifespan? I get the inflammation claim on the surface, but why would Karate promote more inflammation than say weightlifting, crossfit training or something else? The idea that the authors were able to figure out accurately that certain styles were better or worse ofr longevity also sounds a bit ridiculous..I don't see how it would even be possible to account for all the other (possibly more important than Budo) variables that would have played into longevity. On the surface, it looks like a collection of statistics about lifespan, and a ton of speculation on the reasons for them, rather than anything definitive.

The idea that the authors were able to figure out accurately that certain styles were better or worse ofr longevity also sounds a bit ridiculous..I don't see how it would even be possible to account for all the other (possibly more important than Budo) variables that would have played into longevity.

I think the next step would be for the authors of the book to produce it as a bona fide peer-reviewed scientific paper. Once qualified scientists and statisticians have verified the results and conclusions drawn, then a book aimed at the layman will definitely have legs. In the interim, it’s logical to go with the wealth of sides that conclude the opposite and would have other factors as being far more likely to contribute to a reduced lifespan. As I’ve said above, the fact that the books has not been subject to the standard scientific process means that, to me, the need to purchase the book or seriously consider their conclusions is not there.

If the results are as strong as they claim, then publish a peer reviewed paper and that will remove the justified scepticism shown to date.

I work in research and & I think the comment that "once qualified scientists and statisticians have verified the results" is a little harsh. Of the contributing authors two are Associate Professors at a top 50 worldwide university, a thrid contributor is a senior PhD reseracher at a South Australian University (he did the stats) and other contributing authors are practicing doctors - these people are in fact very qualified scientists/stats people.

As for the comment why didn't they publish? I obviuosly do karate and work in reserach, but I persoanlly would probably not take to the time to publish a karate related paper which is outside my professionally quite focused reserach area, simply because I may have contributed to a book on martial arts involving my field (inflammation) would not lead me to doing that when the effects of inflammation on health are far from a novel finding.

In response to the above comment by "Zach Zinn" saying "I get the inflammation claim on the surface, but why would Karate promote more inflammation than say weightlifting, crossfit training or something else?". To me as a reseracher in the area of inflammation and a karate pracctiioner who helps with first aid at tournaments, the answer is obvious - black belts in intense training are typially carrying 3-4 injuries (small fractures, strains, sprains, bruises) at any one time why still in sparring mode & likely when you combine that with lifetime pratice it is quite different to many other sports. The authors in the book did reveiew the published injury rate of karate with other sports to de-conflict some of the different outcomes past studies have found. If you belong to a style where fracture/brusiing type injuries are not pesistant in your dojo I would presume it is a softer style than most (you do not expect weightlifters to to be carrying fractures, burises etc constnatly, and the type of short term inflammation seen from intense workouts has a different inflammatory profile that injuries tha become chronic). The authors walk through the karate dicussions with logical hypotheses on how karate-ka may better the apparent outcomes to health (people in this forum seem to have very black & white views on the topic, the writers of the book and few other scientists would likely view such complex topics in such a binary way).

I work in research and & I think the comment that "once qualified scientists and statisticians have verified the results" is a little harsh. Of the contributing authors two are Associate Professors at a top 50 worldwide university, a third contributor is a senior PhD researcher at a South Australian University (he did the stats) and other contributing authors are practicing doctors - these people are in fact very qualified scientists/stats people.

I think you’re right and my choice of words could have been better. My intent – as I hope the wider post makes clear – was to say that the findings need to be subject to peer review through the normal process (i.e. other qualified people have reviewed the results). I was not suggesting the authors are unqualified. What I was suggesting is that the scientific method demands peer review by other qualified people. And we’ve not had that.

Uqksu wrote:

As for the comment why didn't they publish? I obviously do karate and work in research, but I personally would probably not take to the time to publish a karate related paper which is outside my professionally quite focused research area, simply because I may have contributed to a book on martial arts involving my field (inflammation) would not lead me to doing that when the effects of inflammation on health are far from a novel finding.

Saying that inflammation injuries are bad for health would not be a novel finding; saying, as the authors are, that karate shortens lifespan is something else entirely. They are saying that the practise of karate will shorten lifespan – as an overriding factor which has a greater influence than diet, genetics, etc – and that is a very novel finding.

They are also stating that the well documented benefits of physical exercise are overridden by the specifics of karate. That’s also a very big claim.

There are a huge number of people who practise karate (and very similar arts such as TKD, TSD, etc) worldwide and if the practice is seriously threatening the health of this huge number of people then that should be properly researched and the claim critically examined.

This is not a claim that inflammation injures are bad for health; the book (and promotional video) make an entirely different claim. The have made a strong claim about the dangerous effects karate can have on the health of its practitioners – which runs contrary to existing research – and which can affect the health of 100,000s of people.

I would therefore say they should publish to legitimise the research, to open the claim up to the scrutiny of others in a manner in keeping with the scientific method, to serve the karate community, and, last of all, to ensure the book is seen to have the authority that such a grand claim would demand.

As I’ve said in previous posts, the fact that have not done that means that I would be wise to go with the evidence that is better supported. It also means that I feel OK with dismissing this claim because it is not made from the same position of authority as existing information.

Uqksu wrote:

The authors walk through the karate discussions with logical hypotheses on how karate-ka may better the apparent outcomes to health (people in this forum seem to have very black & white views on the topic, the writers of the book and few other scientists would likely view such complex topics in such a binary way).

I can see them merit in suggesting that some aspects of training could be altered to be more beneficial to health (although they may also make it less practical and enjoyable :-). However, once again, they are making far stronger claims than that. I think that it is strong claims like "the data shows that [karate] takes time off lifespan” - without the evidnce to support it - that is provoking the dismissive response.

A very strong claim that karate will shorten lifespan has been made. This is despite the well documented health benefits of exercise. It’s a very “black and white” conclusion to draw when the detailed background health of those whose ages at death were used in the book have not been factored in.

Does the book know that they all died of? Were autopsies carried out? Where all those deaths directly attributable to karate? No deaths from far more common causes caused by known factors? Because heart disease is a leading cause of death, it would be fair to assume it took out quite a few of those listed. In those cases how can they prove the heart disease came from karate and not some other known cause? And to assume it did would be to ignore the massive amount of verified scientific research that would suggest other known factors are far more likely to be the cause (i.e. lifestyle, diet, genetics, etc).

Kimura is one of the karateka used to provide data for the book (he's even on the cover). He did die of a heart attack at 54. However, as I pointed out in my earlier posts, he was known to be a heavy drinker. Alcohol is a scientifically verified contributory factor to heart attacks (unlike karate). Excessive alcohol consumption can cause high blood pressure and increased blood cholesterol levels, which in turn increase the risk of coronary heart disease. If therefore strikes me as highly unsound to use him as an example of a karate based early death, when it is far more likely that the scientifically proven factor of his drinking was the cause.

There are other heavy drinkers listed too.

Mabuni – who was not a heavy drinker – is another one used as part of the 118. I don’t know his exact cause of death, but he was a very heavy smoker. Based on what we know about the health effects of smoking it’s most logical to assume it was the smoking that was the key issue.

Unless you can rule out these obvious and proven contributory factors it makes no sense to assume karate is the primary cause of when they all died.

The assumption that karate is the overriding factor is very black and white and it’s an illogical conclusion I think we should avoid.

Impact and inflammation are obviously bad for us, but are they really so bad as to override all the known health befits from exercise such that, on balance, karate is likely to have a negative effect on health as opposed to a positive one? I very much doubt it.

For the UK, the five biggest cause of premature death are cancer, heart disease, stroke, respiratory disease & liver disease. Inactively and poor lifestyle choices are known to contribute to all of these.

“A Government report, Living Well for Longer, blames the top five killers for more than 150,000 deaths a year among under-75s in England alone and the Department of Health estimates two-thirds of them are entirely avoidable. Unsurprisingly, leading an unhealthy lifestyle greatly increases your chances of premature death, with smoking, drinking too much alcohol, poor diet, lack of physical activity and being overweight all key contributors to early death.”

The following is from the World Health Organisation website:

"Physical inactivity is now identified as the fourth leading risk factor for global mortality. Physical inactivity levels are rising in many countries with major implications for the prevalence of noncommunicable diseases (NCDs) and the general health of the population worldwide."

"The leading global risks for mortality in the world are high blood pressure (responsible for 13% of deaths globally), tobacco use (9%), high blood glucose (6%), physical inactivity (6%), and overweight and obesity (5%). These risks are responsible for raising the risk of chronic diseases such as heart disease, diabetes and cancers."

These are strong sources that, quite rightly, are pushing for physical activity because of its MASSIVE contribution to good health. It’s simply not tenable in my view to say that impact injuries and inflammation can undo all of that.

If the book had been stating that some aspects of karate are bad for health, then I think we’d all agree with that. A roundhouse to the head is not a beneficial experience ;-) However, there are many aspects of karate which are proven to be very good for health (see above).

The claim being made is that the effects of exercise, social ties, sense of achievement, etc that karate brings – all which have well documented positive effects on health – are being overridden to produce a very black and white result i.e. karate will shorten your lifespan.

So I therefore disagree that discounting a very bold claim by suggesting that more nuance and the consideration of other known factors is needed is the result of black and white thinking. Just the opposite in fact.

My view is that karate is good for health and is likely to increase lifespan based on the well documented effects of exercise. Karate will not protect you from the things that are well documented to decrease lifespan (bad diet, drink, smoking, genetics, etc.), but the positive lifestyle that karate promotes may also promote better lifestyle choices.

There are some aspects of karate that are bad for us – i.e. getting hit – but that’s part of the appeal and nature of what we do. If we sanitise karate too much, it will lose that appeal, so people won’t practise it, and then they lose all the other well-known and scientifically verified health benefits.

It’s also not tenable to say that impact injuries are a greater contributory factor to mortality than inactivity (see WHO reports) such that karate shortens lifespan overall.

I get the point that getting hit is not good for us, that a paper on that is nothing novel, and that there is a place to question the health effects of training. However, the quite different claim that karate will shorten lifespan has been made in a manner which is not in keeping with the scientific method and that runs contrary to the previous findings of that method.

As a layman, I also have concerns about the small sample, the fact that other known factors have not been considered, that fact that the claim runs contrary to other evidence, etc. As a layman, I need experts to be able to critically examine the findings (i.e. scientific peer review of a published paper). If those independent experts support the claim that the hundreds of thousands of karateka worldwide are more likely to die younger, and that the negative aspects of karate far outweigh the well documented positive aspects then that is HUGE and I’m fully on board.

It’s good idea not to take blows too often (I don’t need a peer reviewed paper to tell me that), but the huge and well documented benefits of exercise mean that karate is more likely to increase our longevity as opposed to shortening it. That is where the science takes me.

Because the book has not followed the normal methods for getting such claims accepted by the medical commuity, then I feel happy to discount the claims being made. We have the scientific method to ensure fact gets separated from fiction. If the authors want this to be treated as seriously as the claim being made demands it should, then they need to have the courage of their convictions and publish a paper. I suspect it would get quickly challenged, but I’m happy to be proved wrong. I’m not however going to assume they are right when much stronger evidence would suggest otherwise.

What you are missing in the above is that it is not novel that elite athletes reduce their lifespan, compared to those that simply do moderate exercise (groups like WHO & most federal health organizations suggest & define moderate as the answer). Moderate means: walking, tennis doubles (not singles), gardening, bike riding (but not up hills) etc... What many people call moderate, like running 5 miles four or five times a week, or karate is not in fact moderate i.e the latest reserach suggests a skewed bell curve for the exercise effect on longevity of which inflammation through wear and tear, or injuries, is part of the equation). The fitness industry to a degree is running with an angle that recent data does not back up i.e. difference between health and fitness. I will not quote here the references on this as the book did review all this. And of course it covered off associated hypotheses of the impact of diet (with some stats connected to karate-ka),as well as smoking and karate drinking cuture & karate personality/culture in a balanced way looking for connected links... the book focused on the elite in martial arts, not those who may practice it moderately.

As one other answer to a question you raise, although Mabuni may well have been a heavy smoker, so were all his peers in Japan (and still today a very large percentage of the male population is from what I understand), but he still lived shorter than his Japanese peers of the identical era - the stats are of course run with location and time frame datasets.

Obviously sports and apparent fitness vs health are passionate areas for people and hence the healthy debates. The emerging data on the value/detrement of exercising past a ceratin point, regardless of sport and linked to action type, has been an intriuguing link in particular for reserachers of behavior and inflammation. Also as some of the larger boarder studies have stated on population groups that reach 100 yrs of age, they note that almost none are people who emphasized sport in their lives.

the book focused on the elite in martial arts, not those who may practice it moderately.

There would be little dispute that doing things at an elite level will take its toll. And it won’t be just the training too, for many of the masters listed it will be the stresses of heavy teaching schedules, travel, etc. The point though is that it is then overwork, stress and fatigue that are likely to be the key contributors to any early death. However, the claim was made (at least in the promotional video) that it was karate that was the cause. It’s a false claim.

The bold claim made as “karate: surprising links to lifespan” … but you are saying the book actually states that it’s not karate but overwork? We’ll that’s not particularly surprising either.

I’d still dispute the general idea that karate contributes to a shortend lifespan. That was the claim made and I don’t see that standing up to scrutiny.

Uqksu wrote:

As one other answer to a question you raise, although Mabuni may well have been a heavy smoker, so were all his peers in Japan (and still today a very large percentage of the male population is from what I understand), but he still lived shorter than his Japanese peers of the identical era - the stats are of course run with location and time frame datasets.

You have statistical problems here because you are taking data from one individual when comparted against an average of millions. Variation from the mean average would be expected and no conclusion can be drawn from that. The video promoting the book states, quite correctly, that you can say, “I know a lifelong smoker who lived into his 80s and therefore smoking can’t be bad for you”. It works both ways. My point was that he was a very heavy smoker; which is a known cause of decreased lifespan. It may not have been the smoking that killed him … but it’s far more likely it was that than karate (which has no proven link to decreased lifespan). The authors make the claim it was specifically karate that was the cause and I can see no logical basis for making that claim.

Uqksu wrote:

Obviously sports and apparent fitness vs health are passionate areas for people and hence the healthy debates. The emerging data on the value/detrement of exercising past a ceratin point, regardless of sport and linked to action type, has been an intriuguing link in particular for reserachers of behavior and inflammation. Also as some of the larger boarder studies have stated on population groups that reach 100 yrs of age, they note that almost none are people who emphasized sport in their lives.

I can see that and if you have links to the papers that would add to the thread. If the promotional video had been called, “Overexertion: unsurprising links to lifespan” then I’d have no issue with it. As it was they have made a claim about karate (not overexertion) and hence I would still dismiss the claims made as being totally unfounded.

No I don't consider your summary of my post accurate i.e. "Overexertion: unsurprising links to lifespan”. For example, the longest longevity study run in history by Stanford University dispelled a number of myths on early death. One of the surprises was that those engaged in stressful work/those who worked until later in life actually lived longer (The lay representation of this study was published in a book called the "Longevity Project" & makes for great reading from a variety of standpoints). The book discussed in this thread dissected that work as well to factor into the various hypotheses & data as most 8th Dans obviuosly run organizations and teach a great deal.

It is a little hard to debate in this thread when the people critiquing the material haven't read the 200 pages put together, or read around the field in any depth (I think that was stated by one other poster a little higher up in this thread). I will probably sign off for this thread for now.

It is a little hard to debate in this thread when the people critiquing the material haven't read the 200 pages put together, or read around the field in any depth (I think that was stated by one other poster a little higher up in this thread). I will probably sign off for this thread for now.

As previous stated, the burned of proof is with those making the claim.

“The burden of proof or onus probandi is the obligation on a party in an epistemic dispute to provide sufficient warrant for their position.”

None of us can be experts in everything, nor do we have the time to personally study all the various viewpoints put forth around every single given topic. So we have the scientific method so that claims are tested and peer reviewed. As a result of that process, various trustworthy bodies make policies based on the findings and disseminate the key findings to the general populous.

To give an example, I have not carried out my own detailed research into the amount of alcohol that has injurious effects on the body. I don’t need to because I listen to the advice based on the findings of those that have. The NHS tell me that, “No one can say that drinking alcohol is absolutely safe, but by keeping within these guidelines, there’s only a low risk of causing harm in most circumstances … 3 to 4 units a day for men”.

The blurb for the book says, “With nutritionist Frederick M Beyerlein's system, you'll never get a hangover again. While becoming a 21st century drinker, you'll learn to protect your liver by eating the right foods and replacing the nutrients you lose every time you swallow an alcoholic beverage. Best of all, you'll learn how to really enjoy the high that comes from drinking - without the sickly aftermath.”

Do I need to read that book before I decided to follow what the NHS tells me instead? I’d say not. It’s not based on a scientific study and the bold claims made do not fit with the advice I have received from more trustworthy sources who are giving me information based on scientific studies.

Now, if the drinking book had been through the scientific process, and the findings had been verified, then there maybe something in it. As it it, I don’t feel the need to read the book and it would be foolish of me to place the advice in that book over the advice and evidence put forth by better sources. I feel the same about the “karate will kill you” book.

I can, quite legitimately, and without reading the book, critique the claims made (publically in the video) because they have not followed the scientific method. That alone means they have not acted as the “burden of proof” requires. I can also, in keeping with logic, chose to follow the advice from the innumerable other sources that state karate will be good for me because their claims are based on peer reviewed, scientifically verified information.

The best evidence tells me that inactivity is a killer. The World Health Organisation tells me that "Physical inactivity is now identified as the fourth leading risk factor for global mortality.” That is advice is the result of many studies that have followed the scientific method fully. The authors of this book – in their headline announcement at least – are saying karate will shorten lifespan. Therefore the benefits of karate as physcical activity are rendred null and void such that inactivity may be better form me than karate. That’s a claim that would run contrary to all other advice received.

It also runs contrary to previous studies specifically on the martial arts i.e. “Effects of martial arts on health status: A systematic review” published in the Journal of Evidence Based Medicine (Nov 2010) which concludes that martial arts training had positive health benefits (but that more study was needed).

They also have some things plainly wrong i.e. Funakoshi banned sparring.

“in free sparring there is no set rules as to who will be the attacker or the defender, and so either one may freely attack … [free sparring] maybe compared to an actual duel as in other martial arts where all possible defensive and offensive techniques can be fully used. It is important to keep this in mind and really understand the exquisite mystery inherent in free sparring.” – Gichin Funakoshi, Karate-Do Kyohan

It’s not filling me with confidence that conclusions drawn are sound when we find such glaring factual errors. Again, I feel the presence of such errors is very off putting and makes me all the more less included to buy the book.

If they are truly on to something, then they need to put it out as a scientific paper. That’s the only way the claims can have true validity. Until that time, it makes sense for people to follow the advice of the findings from legitimate scientific studies and be confident that, as things stand, the overwhelming evidence is that karate will help you live longer.

Couldn't help but look back here again. I can't agree Iain with your black and white opinion that the stats were not run correctly, you said "I can critique the claims made (publically in the video) because they have not followed the scientific method.". As I meniotned above, I am an academic researcher by profession and I agree with how the numbers were run (and you have not even looked at how the data was crunched so you cannot make that claim). And as I mentined earlier, contributers for this work came from University positioned people.

They are not saying that small amounts of karate are bad for you (just like helath bodies would agree), the video & the book stress that lifelong elite practitioners appear to be effected (like other elite athlete studies suggest), you keep generalizing and not focusing on the hyopthesis of the "elite" as they do.

We get so little data in the martial arts done in such a fashion and it is a shame for people to dismiss it with out even review. Just my opinions...

I can't agree Iain with your black and white opinion that the stats were not run correctly, you said "I can critique the claims made (publically in the video) because they have not followed the scientific method.". As I mentioned above, I am an academic researcher by profession and I agree with how the numbers were run (and you have not even looked at how the data was crunched so you cannot make that claim). And as I mentioned earlier, contributors for this work came from University positioned people.

I get what you are saying, but I stand by my position as per the previous posts. I explain why I choose to go with better sources in this post:

The argument from authority can take several forms. As a syllogism, the argument has the following basic structure:

A says P about subject matter S.

A should be trusted about subject matter S.

Therefore, P is correct.

The second premise is not accepted as valid, as it amounts to an unfounded assertion that leads to circular reasoning able to define person or group A into inerrancy on any subject matter.

The data has not been published as a paper. It has not been peer-reviewed. That’s not been done and good science demands that it is done. The fact they are well qualified people does not change the fact that the scientific method has not been followed.

The structure of the scientific method inherently prevents appeals to authority by demanding that all claims are subject to the review of others; who will seek to test the claims made. We then have claims that can be verified by others such that the claim rests on its own merits (good science); and not the authority of the person making initially making the claim (a well know logical fallacy). This is what needs to be done here.

Uqksu wrote:

They are not saying that small amounts of karate are bad for you (just like health bodies would agree), the video & the book stress that lifelong elite practitioners appear to be effected (like other elite athlete studies suggest), you keep generalizing and not focusing on the hyopthesis of the "elite" as they do.

In the video they are not soley focusing on the elite as you say they are. Claims are clearly made about all karateka; not just an elite minority (see below). I am therefore right to question these claims.

They asked “karateka” (not “elite karateka”) if they felt karate would increase or decrease their lifespan, the video has the title “karate styles: surprising links to lifespan” and not (as we discussed earlier) “elite athletes: unsurprising links to lifespan” or “overexertion: unsurprising links to lifespan”, etc. From what you are saying, the claim in the book is not the claim they have made in the video. And that’s not good in itself.

The claim, in the video, is unequivocally presented as karate is bad for you. That claim, I simply don’t buy at all for the reasons given.

On the video we are told that 150 karateka were polled at via a website (around 1:50). Most said that they thought karate would increase their lifespan. The principle author of the book directly states on the video that these karateka have a “profoundly wrong opinion as the data shows [karate] takes time off lifespan”.

Are the people polled really “profoundly wrong”? It strikes me that they are not, and a claim is being made here that even their own data does not support … and what it worse this is presented as the headline claim.

Even if we do accept the hypothesis that “elite level” karateka die young there can be no doubt that their data has been misrepresented here.

The karateka polled – who are undoubtedly not all elite level practitioners – would be right to think that karate will increase lifespan (as the various health bodies say it will, and as you agree it will). However, the author states they are “profoundly wrong” which infers that they, as regular karate folks, will have time taken off their life through the practise of karate. That’s not true. It’s a misrepresentation of even their own data. As I say, I’m very confident in rejecting the book due to all these obvious failings; even as a non-statistician :-)

There is also a huge difference between elite level athletes and high ranking lifelong practitioners. Indeed, most elite level athletes are not lifelong practitioners by definition so it’s not right to make the connection with those studies in my view.

Uqksu wrote:

We get so little data in the martial arts done in such a fashion and it is a shame for people to dismiss it without even review. Just my opinions...

The data is being dismissed because it has not been peer reviewed; if it was, it would not be dismissed. The data is being dismissed because they are unclear about the claims they are presenting. The data is being dismissed because there are very clear historical errors presented as fact (Funakoshi allegedly banning sparring, Itosu allegedly claiming karate was bad for health, etc.); If they had got their facts right, I would be less inclined to dismiss it. Above all, all the other evidence – which is not subject to the above flaws and which includes specific studies on the health benefits of martial arts – conclude the exact opposite. Therefore dismissal strikes me as the logical choice and I would suggest that that fault lies with the authors.

They need to publish a paper and have it subject to peer review. They need to make a new video if the claim that karate will shorten lifespan is not actually being made; and instead it is more to do with the elite level training of a tiny minority. They also need to get their facts about karate history right; especially when they are using those claims to bolster their hypothesis. If they do that, then I – like many others – would be more inclined buy the book.

As it is, I think my money would be better going elsewhere (their “Street Fighting Statistics with Medical Outcomes linked to Karate & Bunkai Selection” is a book I have seen and that would be a better purchase). I don’t see the need to buy this one though because it lacks authority (glaring historical errors, failure to have claims peer reviewed in a scientific paper, misrepresentation of findings in promotional video, etc.), it has a lack of clarity in the very bold claims made publicly (marketing?), and there are better sources that I find more trustworthy.

Uqksu wrote:

PS. Don't get me wrong Iain, love your work & love your website, but feel for the above reasons, you cannot make the call you are on the data/should be looking at it differently.

Thanks for the kind words and I get that totally. We have a difference of opinion on this one, and that in no way infers anything other than a difference of opinion. I like those on the forum because it makes for way better threads. I apprecaite you taking the time to challage and express your view.

I do, however, reserve the right to make my own decisions :-) I can make that call. I’m not a scientist; that’s true. But claiming I have to be a scientist to have a viewpoint is back to the logical fallacy of appeal to authority. I am dismissing the calms made in the video because it has not followed the scientific method; which would demand the confirmation or dismissal following testing by other experts. And it runs contrary to the guidance I would be given from other experts; who have had their claims verified by others.

As I said in my last post, I chose to follow the advice on drinking from the National Health Service and not the author of “Drink as much as you want and live longer” - even though he is a nutritionist; and I’m not - not because I’m a qualified expert in the effects of alcohol on the body, but because one has infinitely more authority than the other. I can make that call, and I’m doing a very similar thing here.

While I’m not a doctor or a statistician, one thing I am pretty au fait with is karate history. On that side of things I can directly dismiss the claims made in the video, without the guidance of others, because I know that they are incorrect.

While we will agree to disagree, the thread has defiantly provided an interesting discussion and I’m sure it will prove useful to others when thinking about this topic.

My view remains that practicing karate will be good for health for the vast majority of practitioners, and – as a form of physical activity – it will help increase lifespan. Regular overexertion – such as an elite level athlete will be subject to – may well take its toll, but that will not be an issue for the vast majority of karateka who are not training like elite level athletes. Those that are will be a miniscule percentage. I regard myself as a pretty good karateka, but I know I’m not training like an Olympian!

The bold claims made in the video – which it has been suggested are less bold in the book – don’t have legs and I’m happy to keep training very confident in the view that my lifespan will not be diminished through doing so. Indeed, based on the advice of other more authoritive sources, I am confident my lifespan will be increased through my practice of karate.

What many of these studies using Okinawans from the early part of the century don't take into account is their lifestyle outside of karate and the effects the depredation Okinawa suffered after WWII had on mnay people's health. The karateka were often the first to give their food and care to others.

Many of them smoked like chimneys and drank like fish. But do they take this into account? No, people just want to blame it on karate, and in the case of Goju, sanchin training.
Masanobu Shinjo Sensei was a chain smoker. Miyagi Sensei had health problesm that started during the bleak years after WWII before the allies finally stepped in to provide assistance to Okinawa and was known to give up many things to help others. Miyazato Sensei was a heavy smoker for many years, and the list goes on.
If you want to find a real cause for the shortened lifespan of many of these men, you'll find a much more legitimate reason if you look ath their lifestyle outside of the dojo.

Wow!! What an excellent and lively debate this topic has been to read.

Particularly the back and forth exchanges between Iain and Ugksu. Both sides have some very interesting points of note which were discussed.

However, I am definitely with Iain all the way on this one, based purely on the extremely valid points he raised and the excellent way they were articulated on the post.

For what it's worth, I am a 56 yr old male who does not train at a club anymore (having received my sandan) back in 1991 before I joined the Police (of which I am now retired). I do however still practise karate for a short time daily on a strict Mon - Fri basis at home. This primarily consists of kihon, kata and bunkai mixed in with some callisthenics.

I have absolutely no intention whatsoever of ever ceasing this practice, and to be totally honest, I doubt I would have done so even if any those, dare I say, somewhat "absurd" claims could ever be validated "beyond a reasonable doubt".

How I see it, we are all going to leave this world one day and until then I'm going to do my utmost to enjoy my time as best I can which includes my daily karate (thrown in with a fast car and motorbike to boot, both needed to soothe my ongoing mid-life crisis, lol).

I've got a PhD in a social science and have published in peer-reviewed journals. The view from where I sit is that "published in a peer-reviewed journal" and "true" aren't synonyms. Peer review is one of the best processes we've got, to be sure. But just because a study was subject to peer review and published doesn't guarantee much of anything. Many peer-reviewed studies can't be replicated, for example. Other studies include different variables, or simply different measures of the same variables, and come to very different conclusions. (Just think how many studies have proved eggs, coffee, etc. are killers, then another study proves they're not so bad, etc., ad nauseum.)

Unfortunately, since we can't really do randomized controlled trials on lifestyle, diet, exercise, socioeconomic context, etc., our ability to learn what factors affect health and lifespan is pretty limited. And we only get answers to the questions that are asked, so important causal variables may go unstudied. And there are clear biases to what gets through the peer-review process at some, if not all, journals. Mind-set and ideological biases reign in science as much as they do in other areas of human endeavor.

So while science is a great thing, and I love much of what it can do (I'm using a computer, I've had laser surgery on my eyes, I just flew across the ocean on a plane, etc. - all the results of science!), and I even "do it" for a living, we have to take its limitations seriously. Large, complex, multi-factor, long-term questions in social sciences (and I include lifestyle studies in this) are simply very difficult to answer definitively. So I'd caution everyone not to take even a series of peer-reviewed studies as capital-T truth.

That said, I'm not in any way supporting the original claim that karate shortens life. I have no reason to believe that it does so, and I doubt it does, unless said karate involves receiving a large number of severe beatings...in which case I don't have to worry!

I've got a PhD in a social science and have published in peer-reviewed journals. The view from where I sit is that "published in a peer-reviewed journal" and "true" aren't synonyms. Peer review is one of the best processes we've got, to be sure.

I totally agree. I also hope it was clear I was not suggesting otherwise? The point I was making is that I think we are wise to give more weight to something that has been subject to independent review as opposed to something that hasn’t.

If claim X has been made, and that claim has been put forth for independent scrutiny by other experts in the field, and they also concur that claim x would seem to have validity (accepting that new information can always come along), then the layman can have more confidence in that claim than one that someone has made independently.

There are masses of studies on the positive effect of exercise, and even a good number on the positive effects of the martial arts specifically. Then there is this book that makes the claim that karate will shorten my lifespan. So who do I believe? The lone voice that has not been subject to peer-review? Of the massive of studies that have? Obviously, it will be the latter.

While the scientific process is not perfect, it is set up to try to determine the validity of any claims made. Claims that have been subject to testing via the scientific process therefore have more validity than those that have not.

So while "published in a peer-reviewed journal" and "true" are not synonyms (does science ever claim to have definitive truth anyway?), we can have much more confidence is something that has been through the scientific process.

MCM180 wrote:

So while science is a great thing, and I love much of what it can do (I'm using a computer, I've had laser surgery on my eyes, I just flew across the ocean on a plane

Would anyone have eye surgery if the person doing it was basing his procedure on stuff that he was “sure of”, but that he had not had independently reviewed? Would we get in planes, whose designs had never been tested and whose functionality was based on “I recon” and not scientifically verified information?

I get in planes with full confidence they are not going to fall out of the sky because they have been subject to the scientific process. I’d not fly in one that had not been subject to the scientific process. I’d have no confidence in such a machine.

I am happy to be a mile up in the air in modern plane because the scientific method gives me confidence in it. So much confidence I trust my life to it. I’d not get in one of the above contraptions through!

I feel the same way about this book. It’s not been subject to the scientific process, so there is no reason for me to have any confidence in it. I have confidence in other studies, because they have been subject to that process. So I’m not saying "peer-reviewed" = "true". I’m saying that I have infinitely more confidence in claims that have been subject to the scientific process then ones that have not been.

I therefore have confidence that karate is good for me both in terms of my health and my longevity.

Sorry to ressurect this thread. I have just about finished this and I believe it to be a very important book and all serious karate ka, especially teachers, who look on karate as a lifetime pursuit should read this book or be aware of the issues it raises.

I think it worth touching on some of the criticisms made in this thread. Firstly with respect to peer-review.

This book itself is a review of peer-reviewed literature. It cites 277 peer-reviewed articles, some 13 or so by the author himself. As such, and the nature of the discussion would not be appropriate as a journal publication. One of the cheif criterias for submitting an article for peer review is that it has to substantially add to existing knowledge within the field. The only bit of "new" knowledge added is the statsitical analyses of the longevity of 8th Dan Karate Ka. It could be argued that that might be worth turning into a paper for sports journal, but the analysis of the main thrust of the book is so basic as to be trivial. There are more detailed sub-analysis that probably would merit being published in peer-reviewed form.

Secondly as to expertise - Iain is 100% correct in saying that just because someone is an expert does not make them right. I have seen the fallacy of authority expressed far too much these days - it's pernicious. However, expertise matters. These aren't "just some guys" saying stuff in a book. Their credentials should be regarded as a lo-pass filter, Dr Armstrong is a PhD and 6th Dan life long karate practioner. His perspective on karate and medicine from a life time of study of both should not be dismissed summarily. This book amounts to quite a bit of work, and if we disagree, we can't invoke fallacies of our own because we don't like the conclusions, we should do the work to refute it. That's how sceince progresses. And it's not the same as believing without question - for the time being the evidence presented is the evidence we have.

As to the evidence presented - well there is no detailed statsitical anylsis needed for the central premise. Of the 118 karate pracitioners listed, only 5 of them made it past their life expectency at death. If you were part of this group, you have less than 1 in 20 chance of living to the expected age of death of your cultural group. They control for factors such as genetics and location. For example, Okinawans are as a group realtively very long lived, so the expected age of death is higher there. 118 is absolutely more than large enough sample size. We aren't trying to detect a signal where we have to factor in confidence intervals as well (ie how far from the age death to be statistically significant), 95% of that sample size is more than adequate to qualify it against the null.

The book follows up by examining other sports disciplines and finds similar results for high impact sports. Interestingly, Judo-ka as a group with similar anylses done live PAST expected age of death. Where it gets interesting is in trying to work out why this should be examining the group in more detail. For example, a small number of Okinawans who lived much of their life in the West had significantly shorter lifespans than their counter-parts who remained in Okinawa. The group is too small to be conclusive but given that generally Westerners have much shorter lifespans it's thought that this very likely related to diet. Most of the book examines the literature regarding diet, lifestyle and longevity.

Broadly speaking, they simply review existing thinking regarding longevity and factors associated with problems that affect it, but they do it in a karate-centric way. It's evidenced based, and they ackonoweldge uncertainties and contradictory evidence.

They consider research regarding inflammation and the follow on effects of it, particularly cancer and heart disease, and they look at certain karate practises that might promote it. They look at exercise and longevity and it turns out you only need a very moderate amount of exercise to get the health benefits, according to the peer-reviewed literature they present. More than that has no further benefit and too much will reduce life-span more significantly than if you had been a couch potato. The main factor, in the authors opinion, based on their srvey of published literature is diet. The final summary is that we should be mindful of practises in karate that promote inflamation and should not excerbate that with an inflammatory diet. Simply having a good "healthy" diet is not enough for us, we have to eat low-inflammatory diet in order mitigate the effects of training.

In my opinion, this book is important for karate practioners. There is some logical disconnect if we are training to protect ourselves only to be harming ourselves. And it is a question I personally have had to grapple with in the last few years.

As result from a bout of overtraining in karate a few years ago, on top of nearly 20 years playing a full contact sport, I drove my body into moderately serious long term damage. The information in the book speaks directly to me and it is come a little too late. I am still young enough that I stand fair chance of reversing or mitgating the effects but I have been told by doctors it will take a long time and will always be something I will have to respect. I am personally finding this exremely...challenging. The change in mind-set is extremely uncomfortable.

The problem (and virtue) in karate is the mind-set we try to encourage and it's rather addictive nature. We try to cultivate a never-say-die attitude, and we also try to lead by example if we are more senior. We often try to push ourselves past our limits to develop that indomitable spirit (tamashii), through exhaustion, pain, injury, and that quickly becomes the norm. Not all karate schools are the same, and certain practises if done incorrectly can lead to the chronic inflammation that is so detrimental to health and longevity. But my personal view is that in passing on karate, and in practising it ourselves there must come a point where we have to train for wellness rather than fitness, respect the miles we have put our body through, and be mindful that we don't inculcate habits that may ultimately harm our health or that of our students.

I think this is an important book and it's lessons should be meditated upon.

I would ask if they factors in for known lifestyle issues? Mabuni’s smoking? Kimura’s drinking?

I would also ask if they address the issue that they make claims about karate’s impact on the health of every day karateka when they are reposting on elite level instructors (as someone who teaches and travels a comparable amount I know it can be a stressful lifestyle)?

I still think that the work itself needs peer reviewed. It’s not enough to say that they quote studies that are peer reviewed. Of course that means the sources used as valid, but the methodology that is applied to those sources needs scrutinised by experts. As I say, I can see established reasons why most of the people listed died young (heavy smokers, heavy drinkers, etc). To this layman, not factoring this in seems like a huge oversight. The medical records would undoubtedly be controlled for in any valid scientific study.

I would also add that there is a peer reviewed paper quoted above on the health effects of martial arts that concludes the exact opposite.

I appreciate you putting the other side, especially as someone who has read the book. Personally, I’m still not buying the premise that karate itself is unhealthy. The overwhelming amount of data states that physical exercise is good for us; it would take some strong evidence for me accept that does not apply to karate and that it poses a genuine health risk to the millions who practise it.

If karate does indeed pose a health risk, then that needs properly studied and progressed through the correct channels. Until then, I would recommend people go with what the vast majority of the guidance given by medical authorities based on detailed studies i.e. physical exercise is good for us and when martial arts have been studied through the scientific process they have shown to be an effective and healthy form of exercise. This book alone is making claims to the contrary.

The detrimental effects of overtraining are also well studied. That’s true of any form of exercise. We need to guard against that. However, I see no reasons to make very bold claims about karate itself in that regard.

If they were to explain the 118 sample size (why that number?), make public whether the p-value of 5% was reached with that small sample size, demonstrate how known factors such diet, drink, smoking, etc could be safely put to one side, show how the protocols for such studies had been adhered to, and point to where the findings had been published for peer review, then I, along with many others, would be very keen to know more.

P-values are given. Different types of statistical analyses were undertaken and listed, but if I had a criticsm is that they were occasionally arcane and inconsistent making it difficult for a lay-reader to parse.

They are also stating that the well documented benefits of physical exercise are overridden by the specifics of karate. That’s also a very big claim.

It's not that big a claim and probably wouldn't justify a paper on its own as there have been other peer-reviewed research on similar kinds of activity. They aren't disputing the value of physical exercise (it is discussed). They cite papers regarding physical activity and longevity. It's very interesting.

The bold claim made as “karate: surprising links to lifespan” … but you are saying the book actually states that it’s not karate but overwork? We’ll that’s not particularly surprising either

There is a lot of discussion on the thread regarding "elite" practioners and the toll it takes. This is a fair criticism when we discuss the impact karate. How much is too much? But it misses the wider point.

The point they are making is the effect of chronic inflammation on health and longevity. You do not need to be an elite practioner for karate to take some toll. If you have pre-existing condition, injuried, illness, or even bereavement, stress at work, difficult home life, other forms of stress, these compound. This may not sound surprising at first, but to a lot of people practising karate thinking that they are doing the right thing, relieving stress, getting much needed exercise, they can be further promoting inflammation if they training too much or too heavily. And people do. I've seen it - I've done it. Furthermore it is different for different people. In my opinion, this is something that ought to be considered as part of a general approach to karate as a way of life.

Coincidence does not equal causality. Many karate masters were sickly children who began karate to improve their health, plus all that was mentioned before. That surprising link is not all that surprising.

I would ask if they factors in for known lifestyle issues? Mabuni’s smoking? Kimura’s drinking?

Yes. These are all considered.

For example, they examine differences in dojo culture. Some dojos encourage after training social drinkning, others do not.

They look at Okinawans living in Okinawa as a group, Okinawans and Japanese living in western cultures. They break down the westerners into groups as well looking for clues. but every time you make the group smaller you lose statsitical significance. They even look at marital status. They compare with other types of martial arts and other types of sports. It's pretty thorough.

I still think that the work itself needs peer reviewed. It’s not enough to say that they quote studies that are peer reviewed.

Well, it's a fair point, but I think you be might over estimating the value and importance of peer review. There are many peer reviewed papers that aren't worth the paper they are printed on. Peer review isn't a guarantee of veracity or that the statistical techniques are valid. There are many very celebrated cases where completely invalid statisitcal techniques have passed peer review. All peer reviewers do is simply go through the paper to see if it 1) contributes meaninfully to scientific knowledge 2) whether what has been presented makes sense. They rarely actually check that they have done their sums right or re-do the statistical analysis.

Falling back to "peer-review" is a bit of logical fallacy by authority in itself. Just because it is peer reviewed doesn't make something right. Being right makes something right.

If karate does indeed pose a health risk, then that needs properly studied and progressed through the correct channels. Until then, I would recommend people go with what the vast majority of the guidance given by medical authorities based on detailed studies i.e. physical exercise is good for us and when martial arts have been studied through the scientific process they have shown to be an effective and healthy form of exercise. This book alone is making claims to the contrary.

Again, and I think this has been pointed out, the book does NOT suggest that physical exercise is not good for us. Indeed, it quotes many peer -reviewed articles on the subject. It is also not novel that chronic inflammation is detrimental to health esp heart disease and cancer. They examine and discuss the literature explaining why and how.

When you exercise for fitness, you create an inflammatory event, it releases cytokines and other hormones such as cortisol. Inflammation in the short term is good for us, it signals the body to rebuild and when it does it rebuilds more strongly in order to adapt, so next time you exercise it will do less damage. The same for when you get injured, bruising, muscle strains, ligament strains and so on. It's not unusal for karate ka to train through these. What can happen after a while is that the inflammation becomes chronic, particularly if there are other stress promoting events going on. It's the chornic inflammation that is the issue and there are a lot of things in karate that promote it.

For example, sparring, especially full contact. Ude tanren, conditioning. Or just generally a little too much in the way enormously fun bumps and boisterous application of bunkai. They explain the biochemical process going on, what can lead to heart problems or cancer as a result of chronic inflammation and they discuss contradictory science.

So the detrimental effects of karate are not limited to karate, and they ARE being studied, I presume through "correct channels". The point of this book is to "karate-ify" it for us, to look at that on going research from the point of view of karate practioner.

They are not proposing not doing karate! Come on, mate - he is 6th Dan and a complete karate junkie from the looks of things. He is writing an evidence based approach to examining the question of whether karate promotes longevity, which prior to reading this I believed it do. He looks at practises he thinks may be promoting inflammotry responses (the section on sanchin was interesting) and makes suggestions as to what can be done to mitigate. The key thing he believes is diet.

I should add just for the record, I did not agree with everything in the book. I had a problem with some things here and there, but it was a sober analytic evidecne based approach on a question I think we ought to think about.

The claims you reporting are much smaller than the claims made in promotional video that sparked this discussion. If it’s just that overtraining and getting hit are bad for you then that seems pretty obvious. That’s not the claim first made though.

The claim was made that your average karate (the 150 polled on their website) were “profoundly wrong” if they thought karate (not overtraining or getting hit, but karate in and of itself) was good for them because “the data shows [karate] takes time off lifespan”.

I strongly maintain that for the vast majority of people karate will increase their life expectancy. They are not “profoundly wrong” to think that at all. All the evidence would say they are right to think that. Including actual scientific studies into the effects of martial arts on health and longevity.

The effects of regular exercise has been confirmed time and time again. I will bet my bottom dollar that the 150 polled aren’t all training full contact or so hard that it’s going to result in an early death. It’s totally wrong to make a very strong public claim based on such an outlandish assumption.

Stevenson wrote:

Again, and I think this has been pointed out, the book does NOT suggest that physical exercise is not good for us.

I never said they did. What they did claim was karate would cause the 150 karate polled to die younger that they would have done. That was the claim made. The claimed that karate – which does provide physical exercise – was going to result in early death and people we “profoundly wrong” to think otherwise. Karate is a form of physical exercise and as such I maintain it is going to have a positive effect on the longevity of karateka. The body of evidence would agree with me.

Iain Abernethy wrote:

I would ask if they factors in for known lifestyle issues? Mabuni’s smoking? Kimura’s drinking?

Stevenson wrote:

Yes. These are all considered. For example, they examine differences in dojo culture. Some dojos encourage after training social drinking, others do not.

That’s not enough. Nowhere near enough. Any good medical study would need medical records to accurately account for these things. Anecdotal evidence shouldn’t be used. You’d also need family history for this to be meaningful. I speak as someone whose family members have been in proper scientific studies relating to health and longevity. Great pains were taken to ensure all known variables were accounted for. This meant lengthy interviews, full access to medical records, etc. Nothing close to that seems to have happened here.

I’m pretty sure I’m going to die younger than most. My karate will make me live longer than I would have, but genetics will probably get me in the end. My great-grandfather died at the age I am now. My grandfather in his 50s. My dad has had a triple bypass and is on all kinds of medication. My family has a genetic predisposition to heart disease. So if I was part of this study, would they automatically conclude any early death on my part was a down to karate? It seems they would. Did they have the past master’s medical records so known causes of earth death (lifestyle, illness, family history, etc) can be ruled about before they claim karate is the cause? If there is no medical control you simply can’t make any worthwhile conclusions. It’s not scientific.

In Stephen Jay Gould’s “The Mismeasure of Man” he makes the point that over time the price of Swiss cheese, his age, the population of Mexico, the size of his pet turtle, and the distance between galaxies have all increased and shown strong correlations. However, that does not mean his age increased because any of the other increased. If the Mexican population goes down, he’s not going to get younger. You need to show causation.

For this to have any value they’d need to show that the reason the masters picked died young was because of karate training (including impact and overtraining) and nothing else. When they are not able to control for far more likely causes because of the huge unknowns around lifestyle, family history, etc. then I strongly doubt the validity of any “conclusions” reached.

Again, if all they are saying is that overtraining and getting hit are bad for you then that’s a pretty unexciting claim. I accept that. It's both obvious and well supported.

We need to remember that they publically claimed that karate per se will cause the average karateka to die younger than they would have and that’s palpable nonsense when the effects of exercise are so well established.

As I also mentioned above, I am not a doctor, as scientist, or a statistician … but I am someone who knows a fair bit on karate history. And there is some misrepresentation and partial quoting going on in their promotional material for this book. I could not say if it is deliberate or not, but I can say that the full quotations in context do not support the claims they are making. They would undermine the hypostasis they put forth.

Funakoshi was not anti-sparring as claimed. He did engage in live bouts (he’s clear about this in his autobiography). Itosu did not say that karate caused an early death as claimed (he said that specifically about Sanchin with excessive tension). In fact, quite the contrary, he claimed that karate was good for health, as did Funakoshi. Indeed when Funakoshi did it he pointed to Itosu as someone who lived a long life because of karate.

So when I see the past masters and their view misrepresented to further a claim that seems very questionable for many other reasons, it really does set my alarm bells ringing.

If all that is really being claimed that we karate should not get hit full contact and over train because that can be bad for us, then who would argue with that. That’s not the claim publicly made though.

Looking at the negative effect of getting hit and what can be done to mitigate it seems very worthwhile and there is obviously good data to back all that up. We need to separate that from the unsupportable claims about karate overall – especially as it relates to your average practitioner – and the dubious claims based on the death dates of the masters they looked at. We also need to see that they have – intentionally or unintentionally – presented historical falsehoods to try to lend support to their hypothesis.

I don’t want to get hit hard. I try not to over train. And all the evidence we have tells me that karate will make me live longer because it provides the physical exercise that holds off the things that will eventual kills most of us. Problems resulting from impact injuries are NOT leading causes of death. Problems resulting from inactivity are. The claims they made simply can’t be supported.

The World Health Organisation is clear:

1 - Insufficient physical activity is one of the leading risk factors for death worldwide.

5- More than 80% of the world's adolescent population is insufficiently physically active.

They are not saying the same about impact injuries. It's risk factor certianly; but nowhere near as big a one as inactivity! For their claim to have legs they would need to show that your rank and file karateka over trains and takes so much impact that the proven and hugely beneficial effects of exercise are overridden. It’s just nonsense to assert that. Again, the World Health Organisation are very strong on the benefits of physical activity and that’s based on innumerable studies; not one book. That should be enough for us to conclude karate is good for us because it provides the physical activity that is shown to be a major factor in increasing longevity.

We'd all be smart to avoid overtraining, avoid getting hit hard, and take both precautionary and mitigating measures against both. However, the unassailable truth is that all meaningful evidence from all reputable bodies tells us the claim they made in marketing the book has nothing to support it.

Karate will help you live longer. Any claims to the contrary are unsupportable.